%0 Research Notes %T Tree damage caused by excavating machines in ditch network maintenance %A Lauhanen, Risto %D 1994 %J Suo - Mires and peat %V 45 %N 2 %U http://suo.fi/article/9736 %X An inventory of tree damage caused by five excavators, four backhoes and one small-size single-track backhoe was carried out in western Finland during the frost free season. The proportion of damaged trees was 1.1-2.4 % in tree stands ditched using backhoes and excavators, if the ditch lines had been opened in advance. The corresponding proportion caused by the single-track backhoe was 0.9%, if the ditch lines had not been opened in advance. The damage to tree stands was affected by the machine type, the work type and the width of the opened ditch line. Excavators caused more stem damage in the ditch cleaning than backhoes did (p<0.02). The mean distances of the damaged trees from the center line of the ditch were 226-264 cm on the work sites ditched using backhoes and excavators. The mean DBH of the damaged trees was 8-10 cm depending on work and machine type. The optimum width of the ditch line for the different machine types was assumed to be 400-500 cm when considering the growth losses of tree stand, the tree damage and the work productivity. Keywords: backhoe, ditch cleaning, ditch digging, environmental protection, excavator, forest drainage, work studies R. Lauhanen, The Finnish Forest Research Institute, Kannus Research Station, FIN-69101 Kannus, Finland